Slice beef into 1/2-inch thick slices and place at the bottom of the crockpot.
Chop bell peppers and onion into large chunks; mince garlic. Place on top of beef.
Whisk together the broth, salt, pepper and Sriracha sauce. Pour over the beef and cook on high for 3 1/2 to 4 hours, or until beef is tender.
About 30 minutes before the beef is done, cook rice according to package directions.
In a small pot, mix water and corn starch. Whisk in 1 cup of liquid from crockpot and bring to a boil over medium heat. Cook for 2 minutes, stirring continuously. Return sauce to crockpot and stir.
Place beef and veggies on a bed of rice, garnished with parsley if desired. Serve with pineapple on the side.